Lackmischungen

摘要

1,232,162. Polyacrylate- and polyurethanecontaining coating lacquers. FARBENFABRIKEN BAYER A.G. 27 June, 1969 [10 July, 1968], No. 32577/69. Heading B2E. [Also in Division C3] Lacquer mixtures comprise at least one polyacrylate resin which contains carbonamide groups, is free from hydroxyl groups and has a molecular weight above 600, and at least one poly-N-alkoxymethyl urethane as cross-linking agent. The polyacrylate resin is a copolymer of (meth)-acrylamide with acrylic or methacrylic acid or an ester or nitrile thereof and, optionally, one or more other comonomers, e.g. allyl ethers, vinyl esters, maleic esters, styrene and vinyl toluene. The carbonamide groups of the polyacrylate resin may be partly reacted with formaldehyde and etherified. The poly-N-alkoxymethyl urethane is a reaction product of an N-alkoxymethyl urethane and a low or high molecular weight polyol. Suitable solvents for the lacquer mixtures include toluene, xylene, chlorobenzene, ethyl acetate, butyl acetate, #-methoxyethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethanol, butanol, ethylene glycol and mono-(C 1 -C 4 -alkyl) ethers thereof, and butylene glycol. The mixture may optionally include a melamine-formaldehyde or urea-formaldehyde resin; other optional components include inorganic or organic pigments, e.g. titanium dioxide, fillers, aluminium, bronze or zinc dust (anti corrosive and decorative agents), alkyd resins, adipate or phthalate plasticisers, levelling agents such as cellulose acetobutyrate, and acidic cross-linking catalysts, e.g. p-toluene sulphonic acid, phosphoric acid or maleic acid. Coatings obtained with the lacquers are cured by stoving. The lacquers are useful for application to implements and tools, for coating the insides of tins, for use as motor car lacquers, as luminous paint lacquers, for the production of chemically resistant protective coatings and for coating metallic tape. In Examples the lacquers are applied, by spraying, to degreased steel sheets which, in some cases, have first been treated with zinc phosphate or polyvinylbutyral-phosphoric acid zinc chromate.